Radiotelephones generally refer to communications terminals which provide a wireless communications link to one or more other communications terminals. Radiotelephones may be used in a variety of different applications, including cellular telephone, land-mobile (e.g., police and fire departments), and satellite communications systems.
Many radiotelephones, particularly handheld radiotelephones, employ externally-mounted antennas. Externally-mounted antennas are conventionally connected to internal radio frequency (RF) circuitry (i.e., a transceiver) via a coaxial connector, or other electro-mechanical device. Unfortunately, these connecting devices may contribute to a loss of RF signal strength. In addition, these connecting devices may be somewhat expensive, thereby adding to the manufacturing costs of radiotelephones. An externally-mounted antenna and its connector may be subject to damage or failure when a radiotelephone is dropped or subjected to other impact forces. Furthermore, mechanical portions of these connectors may become unreliable over time.
Efforts to eliminate externally mounted antennas have met with limited success, however. An antenna that is incorporated entirely within a radiotelephone housing may be a poor radiator because of the close proximity of the antenna to various electronic components within the radiotelephone, and because of the close proximity of the antenna to the body of a user. Close proximity of an antenna to internal electronic components and to the body of a user during operation of a radiotelephone may result in degraded signal quality or fluctuations in signal strength.
Efforts to develop internally-mounted antennas have also been affected by the current trend of radiotelephone miniaturization. Indeed, many contemporary radiotelephones are only 11-12 centimeters in length. As radiotelephones decrease in size, the amount of internal space therewithin may be correspondingly reduced. A reduced amount of internal space may make it difficult for internally-mounted antennas to achieve sufficient bandwidth and gain necessary for radiotelephone operation in single or multiple frequency bands because antenna size may be correspondingly reduced.